Monthly Archives: May 2012

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I don’t know if I could watch a whole feature film like this, but it’s mighty pretty in two minutes-plus of full-screen viewing. And hey, just as I was wondering if there would be Joshua trees, there were Joshua trees.

And check out the casting: Hugh Jackman is Jean Valjean (yay!), Russell Crow is Javert (um, okay). The Thénardiers will be played by Sacha Baron Cohen and Helena Bonham Carter. And in a particularly nice touch, the Bishop of Digne will be played by Colm Wilkinson, who was Valjean in the 1985 cast.

First, most obviously, how is it that a species is able to come into a new environment that it is not adapted to, surrounded by new environmental conditions and foreign biological interactions, and thrive? Thrive so exaggeratedly, that it can out-compete and displace species which have been there for millennia, adapting precisely to those environmental conditions and biological interactions? How can an individual survive to propagate a population? How can any species accomplish this? Second, less obviously: why can’t more species do it? Humans transport animals and seeds (and spores and larvae, etc, etc) around all the time, but only 10% establish self-sustaining populations, and only 1% spread to new habitats, becoming potentially invasive; this is known as the ‘tens rule’ (Williamson 1993) – a funny ‘rule of thumb’ for which I could never quite figure out the math.

A Biologist went down to the coffee shop one day, because the walk out to the edge of the University campus provided some brief respite from the laboratory. Along the way the Biologist encountered an Evolutionary Psychologist, who was also going to the coffee shop, and they fell to walking together.

As they entered the coffee shop, they found it crowded with undergraduates, for it was almost Finals Week. Accordingly, they joined the long queue of prospective customers waiting to place an order. Said the Evolutionary Psychologist to the Biologist, “My dear colleague, do you not see this crowd of fertile young people as I do, engaged in a dance of mate selection and competiton that predates our ancestors’ descent from the trees?”

And the Biologist replied, “I don’t believe that our ancestors had access to steamed milk and espresso. Or free wi-fi.”

“You are being amusingly obtuse!” chortled the Evolutionary Psychologist. “The environment may have changed somewhat since the days of our Darwinian origins, I will allow, but ova remain much dearer than sperm cells.”

“That much is certainly true,” said the Biologist. “But I am not sure how much it matters to the coffee-shop flirtations of undergraduates, almost none of which will result in procreative intercourse.”

“Ah,” said the Evolutionary Psychologist, “Perhaps this is a subject wherein my own field has surpassed the expertise of yours, my dear colleague. For instance, we have recently discovered [PDF] that men are more attracted to unintelligent, inattentive women—precisely what one would expect if men have been naturally selected to seek out easy opportunities for impregnation. And this search is doubtless underway all around us at this very moment.”

“That is a remarkable and possibly misogynistic hypothesis,” said the Biologist. “I am most curious to know how it was tested.”

“O! It was most elegantly done,” said the Evolutionary Psychologist. “Some of my colleagues simply asked a small class of undergraduate psychology students—males, of course—to examine photographs of women which were previously selected for their various appearances of vulnerability, and tell whether the photographs indicated vulnerability to sexual exploitation, suitability for a one-night stand, and suitability for a long-term relationship.”

“I see,” said the Biologist.

“Most surprisingly,” continued the Evolutionary Psychologist, “My colleagues discovered that the young collegiate males felt that women who looked drunk, or were standing in compromising postures, or indicating vulnerability in any of a dozen different ways, were both more vulnerable to sexual assault and more suitable for a brief sexual dalliance—but not more suitable for matrimony.

“So you see, my dear Biologist, it is not we Evolutionary Psychologists, who proposed the hypothesis of sexual exploitability, that are misogynists—the only misogynist here is Natural Selection itself, which confirmed our hypothesis.”

“I must beg your pardon, dear colleague,” said the Biologist, “but I am afraid I do not understand the basis for your conclusion. In order for this discovery to have any bearing on reproductive success, is it not the case that most human reproduction would need to occur via coerced intercourse?”

“I must confess that this seems to be what the data indicate,” replied the Evolutionary Psychologist. “But we must not conclude therefrom that all men are rapists! By no means, dear colleague. I think it is quite plain that this result demonstrates no more then that all men are potential rapists.”

“But I remain perplexed!” said the Biologist. “Surely rape is an inefficient way to reproduce, since babies traditionally require a good deal of care after impregnation, and women have long known how to un-plant unwanted seeds.”

“That,” said the Evolutionary Psychologist, “is an important question to be resolved by additional study! But of course it need only be the case that the occasional coercive impregnation could increase a man’s reproductive success, however slightly, for Natural Selection to grab hold.”

“I suspect,” said the Biologist, “that you attribute greater efficiency to Natural Selection than this evolutionary force truly possesses, my dear colleague. But even if drunken collegiate hook-ups were a viable avenue for procreation, you must concede that there would needs be some genetic basis for the tendency to reproduce in this fashion, if Natural Selection is to act upon it. Do you truly believe this to be the case?”

“What a peculiar question!” exclaimed the Evolutionary Psychologist. “I thought that you Biologists were well aware that, in the absence of evidence to the contrary, it is quite safe to assume that any and all aspects of human nature have a heritable genetic basis. Would you truly require the demonstration of heritability in order to conclude that an observed trait or behavior is adapted by Natural Selection?”

“Indeed we would,” said the Biologist. “Such a demonstration, in the case of a tendency to sexual coercion, would be considered most remarkable in its own right, in the scholarly journals of my discipline.”

“What a boring and backward discipline you practice!” said the Evolutionary Psychologist. “Truly, it is no wonder that your field has seen no great advance this last half-century, even as we Evolutionary Psychologists dissect the very nature of humanity.”

“Your ambitions,” said the Biologist, “are indeed remarkable.”

At this juncture, the two colleagues found that they had reached the front of the queue, placed their orders, and went their separate ways.◼

Via Bora Zivkovic: Today over a thousand people gathered in Newton, North Carolina, to protest reprehensible anti-gay remarks made by a local pastor. Which, good for them! But when you stage a protest against proposing to basically put gay people in concentration camps (or, let’s be fair: dude actually proposed just one big concentration camp), you’ve got to expect that there will be some counter-protesters. And you never know who you’ll meet counter-protesting a protest against a proposed homocaust:

Earlier in the day, one counter protester was caught off guard when a peacekeeper working with protest organizers to keep participants separated from counter protesters saw someone he recognized. The peacekeeper told [this reporter] that one of the counter protesters, a man in his mid-20s or early-30s, once hit on him at a local adult bookstore. The counter protester denied the accusation while holding a sign that condemned gays. The counter protester left the protest early. [Emphasis added.]

Way to break free of the stereotypes, counter protester dude! How does that line go? … Then they came for the lesbians and the queers, and I enthusiastically endorsed that idea, because no way am I into that sort of thing regardless of what you heard and anyway even if I was, speaking hypothetically, it was just some sinful experimentation in college and then many, many times again after college.◼

I’ve been trying to come up with something profound to say about this ever since I first saw it on Slog, but I don’t know what more to add to the statement: in 1989, the State of Texas executed Carlos DeLuna for a murder he very clearly didn’t commit.

Carlos DeLuna was arrested, aged 20, on 4 February 1983 for the brutal murder of a young woman, Wanda Lopez. She had been stabbed once through the left breast with an 8in lock-blade buck knife which had cut an artery causing her to bleed to death.

From the moment of his arrest until the day of his death by lethal injection six years later, DeLuna consistently protested he was innocent. He went further – he said that though he hadn’t committed the murder, he knew who had. He even named the culprit: a notoriously violent criminal called Carlos Hernandez.

The two Carloses were not just namesakes – or tocayos in Spanish, as referenced in the title of the Columbia book. They were the same height and weight, and looked so alike that they were sometimes mistaken for twins. When Carlos Hernandez’s lawyer saw pictures of the two men, he confused one for the other, as did DeLuna’s sister Rose.

What happened was: Carlos DeLuna was unfortunate enough to witness Carlos Hernandez attacking Wanda Lopez, and ran off. The police found him near the crime scene, hiding under a truck, and almost immediately confirmed that he matched witness descriptions of Hernandez. Having a suspect, the police barely conducted any further investigation into the murder. More from Pilkington:

Detectives failed to carry out or bungled basic forensic procedures that might have revealed information about the killer. No blood samples were collected and tested for the culprit’s blood type.

Fingerprinting was so badly handled that no useable fingerprints were taken. None of the items found on the floor of the Shamrock – a cigarette stub, chewing gum, a button, comb and beer cans – were forensically examined for saliva or blood.

There was no scraping of the victim’s fingernails for traces of the attacker’s skin. When Liebman and his students [the authors of the investigative report] studied digitally enhanced copies of crime scene photographs, they were amazed to find the footprint from a man’s shoe imprinted in a pool of Lopez’s blood on the floor – yet no effort was made to measure it.

People interviewed for the investigation even confirmed that Hernandez repeatedly confessed to the murder. But it was Carlos DeLuna who was executed by lethal injection on the 8th of December, 1989.

The U.S. legal system is, at the most fundamental level, people. People can get things wrong. When the legal system is able to punish people by killing them, that means that the legal system can kill the wrong person. And now, if you need an example of someone who was wrongfully put to death in our country, you have a name: Carlos DeLuna, sacrificed to our society’s insistence that we should be able to punish death with death.◼

It is a truth universally acknowledged in evolutionary biology, that one species interacting with another species, must be having some effect on that other species’ evolution.

Actually, that’s not really true. Biologists generally agree that predators, prey, parasites, and competitors can exert natural selection on the other species they encounter, but we’re still not sure how much those interactions matter over millions of years of evolutionary history.

On the one hand, groups of species that are engaged in tight coevolutionary relationships are also very diverse, which could mean that coevolution causes diversity. But it could be that the other way around: diversity could create coevolutionary specificity, if larger groups of closely-related species are forced into narower interactions to avoid competing with each other.

Part of the problem is that it’s hard to study a species evolving over time without interacting with any other species—how can we identify the effect of coevolution if we can’t see what happens in its absence? If only we could force some critters to evolve with and without other critters, and compare the results after many generations …

A team of evolutionary microbiologists has performed exactly the experiment I outlined above. The study’s lead author is Diane Lawrence, a Ph.D. student in the lab of Timothy Barraclough, who is listed as senior author.

For the experiment, the team isolated five bacterial species, of very different lineages, from pools of water at the bases of beech trees—ephemeral pockets of habitat for all sorts of microbes that break down woody debris, dead leaves, and other detritus. They cultured the bacteria on tea made from beech leaves, in vials containing either a single species, or all five species, and let them evolve for eight weeks—several dozens of bacterial generations. In a particularly clever twist on standard experimental evolution methods, they also used nuclear magnetic resonance (NMR) to identify the carbon compounds in sterilized tea that had been “used up” by the bacterial cultures, and compared the compounds in fresh beech tea to determine what the bacteria were eating.

And, maybe not surprisingly, the bacterial species’ evolution with company turned out to be quite a bit from their evolution alone. Left alone, most of the species evolved a faster growth rate. This is a common result in experimental evolution, because the process of transferring evolving bacteria to fresh growth medium—”serial transfers” that were performed fifteen times over the course of the experimetn—can create natural selection that favors fast-growing mutants. But, grown all together in the same tube, species that had evolved faster growth rates in the solo experiment evolved slower growth instead.

To find out what had evolved in the multi-species tubes, the team tested the growth of the bacterial species on beech tea that had been used to grow one of the other species, then sterilized. The original, ancestral strains of bacteria generally had negative effects on each others’ growth—they lived on similar compounds in the beech tea, and so their used tea wasn’t very nourishing for the other species. The same thing occurred with the strains that had evolved alone, only stronger, which makes sense in light of the increased growth rates, which would’ve depleted the growth medium faster.

But the interactions among the strains of the different bacterial species that had evolved together was strikingly different. Many of them actually made the tea more nutritious for other species in the evolved community. That is, some of the bacteria had evolved the capacity to eat the waste products of another species that was evolving with them. Using the NMR method to track changes in the presence of different carbon compounds in the tea before and after use provided confirmation that the co-evolved species were using, and producing, complementary sets of resources.

In short, the evolving community didn’t simply become more diverse—it evolved new kinds of mutually beneficial relationships between species that began as competitors.

That evolutionary shift toward mutual benefit had a significant impact on the bacterial community as a whole, too. Lawrence et al. assembled new communities of bacteria extracted from the end-point of the group evolution experiment, and compared their carbon dioxide production, a proxy for overall metabolic activity, to that of a community assembled from bacteria extracted from the end point of the solo-evolution experiments. The community of co-evolved bacteria produced significantly more carbon dioxide, suggesting they were collectively able to make more use out of the growth medium.

So that’s a pretty nifty set of results, I have to say. But I’m also left wondering what it tells us more generally. In both Lawrence et al.‘s paper, and in accompanying commentary by Martin Tucotte, Michael Corrin, and Marc Johnson, there’s a fair bit of emphasis on the unpredictability of the result. Lawrence et al. write, in their Discussion section,

The way in which species adapted to new conditions in the laboratory when in monoculture—the setting assumed for many evolutionary theories and experiments—provided little information on the outcome of evolution in the diverse community.

And, as Corrin et al. note,

These results imply that predictions constructed from single-species experiments might be of limited use given that most species interact with many others in nature.

So … evolution went differently under different conditions? That isn’t exactly a shocking revelation. The fact that this is one of the study’s major conclusions is a symptom of how little experimental work has actually tested the effects of multiple species on evolution. One experiment I’ve discussed here previously, focused on the joint effects of predators and competitors on microbes that live in pitcher plant pitfalls, similarly emphasized the fact that it wasn’t possible to predict the evolutionary effects of predators and competitors together based solely on their individual effects. Work in this line of inquiry is hanging at the point of establishing that complex conditions lead to complex results.

What I’d really like to know—and I think all the authors of both the paper and the commentary would agree with me on this—is how we can begin to make general predictions about community evolution beyond, “it depends what we put in at the start.” It may be that we’ll need a lot more studies like this current one before we can start to identify common processes, and more interesting trends.◼

As J.B.S. Haldane put it, “I think … that the public has a right to know what is going on inside the laboratories, for some of which it pays.” He was referring to the need for scientists to explain their work in popular media—which, amen, brother Jack!—but the point holds with regard to access to original scientific articles, too.

It doesn’t make much sense that U.S. citizens, whose taxes fund most of the basic science in this country, are then expected to pay upwards of $50 for a single PDF copy of a journal article presenting government-funded research results. The National Institutes of Health already requires that research it funds be archived online and accessible to the general public free of charge—why not expand that to all government-funded research? And hey, there’s a way to suggest exactly that out to the man in charge: a petition on WhiteHouse.gov.

We believe in the power of the Internet to foster innovation, research, and education. Requiring the published results of taxpayer-funded research to be posted on the Internet in human and machine readable form would provide access to patients and caregivers, students and their teachers, researchers, entrepreneurs, and other taxpayers who paid for the research. Expanding access would speed the research process and increase the return on our investment in scientific research.

The highly successful Public Access Policy of the National Institutes of Health proves that this can be done without disrupting the research process, and we urge President Obama to act now to implement open access policies for all federal agencies that fund scientific research.

It needs 25,000 virtual signatures within 30 days before it’ll get any meaningful attention, so sign this thing and then start badgering all your online “friends” about it, why don’t you? Especially the jerks who keep filling your update stream with branded product promotions and/or time-sucking adorable cat videos and/or news about how they’ve just spent real money for a virtual cow—post this directly on their “walls,” if those are even still a thing, with or without a witty and/or pleading comment appended.

I mean, it’s Monday morning; it’s not like you’re going to get do anything else for the benefit of humanity in the next minute or two, you slacker.◼